The present invention relates in general to fluid-flow control valves, but particularly to fuel injectors for internal combustion (i.c.) engines.
A fuel injector for an i.c. engine normally consists of a valve which, in use, allows fuel to be injected under pressure into a cylinder for combustion. The timing of fuel injection into a cylinder can be reasonably accurately controlled by mechanical means but normally, in the case of a multi-cylinder i.c. engine, the mechanical means does not allow for separate adjustment of fuel injection timing for any one of said cylinders.
Electronic management systems for i.c. engines are now known wherein fuel injection to each cylinder is electronically controlled according to predetermined sequences. Such systems can include sensing means for feeding back to the management system signals indicative of engine timing events which allows the system to separately adjust subsequent timing events for fuel injection into each cylinder according to pre-programmed processes.
Whilst such management systems have been shown to improve engine performance regarding fuel consumption and exhaust emissions, for example, the ability of the system to improve engine performance relates directly to the accuracy of the system's control of timing events which itself depends upon the accuracy of the information the system receives regarding actual timing of fuel injection into each cylinder.